Changing display language has no effect
Steps to reproduce
Mattermost Version: 5.4.0 on Ubuntu 18.04
The configuration has locale de as default and offers de and en as options.
Switching in the account settings should switch the language. New signups should see Mattermost in de locale.
Everything remains consistently in locale en. No indication of trouble in the logs.
I have no idea where to look for solving this.
I also created an SO question on this: https://stackoverflow.com/questions/53459887/changing-display-language-has-no-effect-in-mattermost